Ah! the give and take of technological research makes great reading. I am
rushing upstairs to the mirror as we speak.
Does not compute!
The centre of mass of the trim tab AND the extra lead/steel needed to
counterbalance it is forward of where tail ballast would be added. So more
weight in total will be needed. This is the same principle as your (correct)
argument for incurring additional total weight for a battery mounted in the
rear.
The point I> was making was that given the trim tabs are at the rear, any
extra weight> (although absolutely minimal in any case) wouldn't effect the
weight of
the> aircraft since you would simply require less lead in the fin for final
balance.
>Mounting the battery in the luggage bay area might negate the need for lead
>in the fin but will increase overall weight because of the heavy cable runs
>required.
> > Actually, it means more lead in the aircraft, because any additional
weight
> > in the Fletner strips has to be counterbalanced!
err! ! ! - I think we're arguing about semantics here.
Both the extra weight of the hardwood trim tab and the increase in
counterbalance weight is still significantly rearward of the aircraft's Cof
G. The combined mass of stabilator and counterbalance has a C of G
coincident with the torque tube. Sure, strictly speaking, as the lead in
the fin post is rearward of the torque tube, a lighter stabilator will
result in a very slightly lighter finish due to the slight rearward position
of the lead weight exerting an increased and more effective moment. In
practise, this longitudinal difference- torque tube to fin post - tends to
zero and therefore the weight of the stab assembly will have very little
effect on overall aircraft weight.
There comes a point where you have to consider practical reality rather than
worrying about every last nanogram! - The point I was making was that, given
a weight disadvantage of effectively zero, I would prefer not to pratt
about with balsa but use something more serviceable and durable - common
sense really. If it remains an issue for anyone - use hardwood flettners
for robustness and then pluck your nasal hair before you fly in order to
achieve the same end result! !
Having the habit of reading the bottom line first, I came across this
beauty:
> for robustness and then pluck your nasal hair before you fly in order to
> achieve the same end result! !
Makes you scratch your head as well eh :-)
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